"I warned (Stone) repeatedly during the 2016 summer, do not associate yourself with Julian Assange," Nunberg said in an interview on CNN's "New Day."

When asked how Stone, a longtime adviser to President Donald Trump, responded to his warnings, Nunberg said, "Roger is going to do what Roger is going to do."

"Roger's advised me not to do certain things. We're very stubborn people," he said of the man he calls his mentor.

Stone, who briefly served as a Trump campaign adviser early in the race, is a subject in the special counsel's investigation, Nunberg told CNN last week.

On Tuesday, The Washington Post reported, citing an anonymous source, that Stone claimed to have had contact with Assange in 2016. In the same report, Nunberg said Stone told him he met with Assange. Stone denied Nunberg's claim to the Post, recalling that he told Nunberg he was going to meet with Assange -- but as a joke Nunberg misinterpreted.

Stone told CNN Tuesday that Nunberg "was too intense to figure out it was a joke."

Stone has strongly denied he had any direct contact with Assange, despite earlier public claims that he's spoken with him. WikiLeaks has said it has never been in contact with Stone.